ATL: HARVEY - Post-Tropical - Discussion

[GCANE]

TUTT over western Cuba could be weakening a bit.
Moisture filling in and 200mb vort a bit less strong.

[cycloneye]

Tropical Storm Harvey Discussion Number 6
NWS National Hurricane Center Miami FL AL092017
500 PM AST Fri Aug 18 2017

Again, there has been little change in the structure of Harvey,
with the low-level center near the eastern edge of a strong, but
poorly organized, convective area. Earlier reports from an Air
Force Reserve Hurricane Hunter aircraft included winds suggesting
an increased intensity. However, due to uncertainties in how
representative these measurements were, no appreciable change in
the central pressure, and no improvement in the structure, the
initial intensity is held at 35 kt.

The initial motion is 275/18. A strong low- to mid-level ridge
north of the cyclone should keep Harvey on this general motion
for the next 3 days or so, with the system moving from the eastern
to the western Caribbean Sea during this time. After 72 h, a
west-northwestward motion with a decrease in forward speed is
expected when Harvey passes near or over portions of Central
America, the Yucatan Peninsula, and eastern Mexico. The new
forecast track is a little faster then the previous track, but
there were only minor changes in the direction. It should be noted
that there is considerable uncertainty about how far north Harvey
might get over the Bay of Campeche, with several of the large-scale
models not bringing the center back over the water on the latest
runs.

The current shear should persist for about the next 48 h, and
thus the intensity forecast continues the trend of slow
strengthening during this time. However, the GFS and ECMWF again
forecast Harvey to degenerate to an open wave during this time, and
the rest of the intensity guidance has trended toward a weaker
cyclone. This lowers the confidence in intensification. After
48 h, conditions appear more favorable for strengthening, with the
main uncertainty being how much land Harvey will encounter. The
intensity forecast will again call for a peak intensity of 60 kt in
72 h, followed by weakening due to land interaction.


FORECAST POSITIONS AND MAX WINDS

INIT 18/2100Z 13.4N 62.9W 35 KT 40 MPH
12H 19/0600Z 13.6N 65.7W 35 KT 40 MPH
24H 19/1800Z 13.9N 69.3W 40 KT 45 MPH
36H 20/0600Z 14.2N 73.0W 40 KT 45 MPH
48H 20/1800Z 14.5N 76.7W 45 KT 50 MPH
72H 21/1800Z 15.5N 83.5W 60 KT 70 MPH
96H 22/1800Z 17.5N 88.5W 50 KT 60 MPH...INLAND
120H 23/1800Z 19.0N 92.0W 30 KT 35 MPH...OVER WATER

$$
Forecaster Beven

[chaser1]

With the latest discussion laying everything out, i'm gonna go out on a limb here. Assuming that Harvey will have at least maintained its identity as a closed system, I believe that the storm will undergo some significant strengthening at its crossing 70W and within the 24-36 hr. period. I'll further guess that Belize or Yucatan will have to brace for a Cat. 2 or 3 hurricane. As I see it, the cut-off centered over the Florida Straits will continue to not only move westward but more importantly will gain latitude as well. I think that the shear impacting Harvey now will lesson in about 24 hours as the storm moves a little further west and that we'll see a broader upper anticyclonic flow begin to bridge south and over the Central Caribbean. Obviously no models seems to think that and NHC seems to be hinting towards possibly better upper conditions but further out than that. Hmmm, maybe I wont quite bet the farm on it LOL; better I keep it to a 6-pack of beer!

[Thetxhurricanemaster]

With the latest discussion laying everything out, i'm gonna go out on a limb here. Assuming that Harvey will have at least maintained its identity as a closed system, I believe that the storm will undergo some significant strengthening at its crossing 70W and within the 24-36 hr. period. I'll further guess that Belize or Yucatan will have to brace for a Cat. 2 or 3 hurricane. As I see it, the cut-off centered over the Florida Straits will continue to not only move westward but more importantly will gain latitude as well. I think that the shear impacting Harvey now will lesson in about 24 hours as the storm moves a little further west and that we'll see a broader upper anticyclonic flow begin to bridge south and over the Central Caribbean. Obviously no models seems to think that and NHC seems to be hinting towards possibly better upper conditions but further out than that. Hmmm, maybe I wont quite bet the farm on it LOL; better I keep it to a 6-pack of beer!

Lol if that came to fruition the trough would definitely pull it due Northward !!!

[Thetxhurricanemaster]

Guys what time does the next recon leave ? Can yall please tell me

[chaser1]

With the latest discussion laying everything out, i'm gonna go out on a limb here. Assuming that Harvey will have at least maintained its identity as a closed system, I believe that the storm will undergo some significant strengthening at its crossing 70W and within the 24-36 hr. period. I'll further guess that Belize or Yucatan will have to brace for a Cat. 2 or 3 hurricane. As I see it, the cut-off centered over the Florida Straits will continue to not only move westward but more importantly will gain latitude as well. I think that the shear impacting Harvey now will lesson in about 24 hours as the storm moves a little further west and that we'll see a broader upper anticyclonic flow begin to bridge south and over the Central Caribbean. Obviously no models seems to think that and NHC seems to be hinting towards possibly better upper conditions but further out than that. Hmmm, maybe I wont quite bet the farm on it LOL; better I keep it to a 6-pack of beer!

Lol if that came to fruition the trough would definitely pull it due Northward !!!

Perhaps. I dont think it would to the extent that the E. Gulf would have to worry about it; but I could see that set up aid in its gaining enough latitude to pose a potential threat to your guys in Texas.

[Thetxhurricanemaster]

With the latest discussion laying everything out, i'm gonna go out on a limb here. Assuming that Harvey will have at least maintained its identity as a closed system, I believe that the storm will undergo some significant strengthening at its crossing 70W and within the 24-36 hr. period. I'll further guess that Belize or Yucatan will have to brace for a Cat. 2 or 3 hurricane. As I see it, the cut-off centered over the Florida Straits will continue to not only move westward but more importantly will gain latitude as well. I think that the shear impacting Harvey now will lesson in about 24 hours as the storm moves a little further west and that we'll see a broader upper anticyclonic flow begin to bridge south and over the Central Caribbean. Obviously no models seems to think that and NHC seems to be hinting towards possibly better upper conditions but further out than that. Hmmm, maybe I wont quite bet the farm on it LOL; better I keep it to a 6-pack of beer!

Lol if that came to fruition the trough would definitely pull it due Northward !!!

Perhaps. I dont think it would to the extent that the E. Gulf would have to worry about it; but I could see that set up aid in its gaining enough latitude to pose a potential threat to your guys in Texas.

Of course that's what I meant ! Yeah the Weather Channel says it could impact the Texas coast next week so it's definitely something to watch half of the models are split .... HWRF takes Harvey due North into the Gulf now ! It's a dangerous trend

[Cunxi Huang]

Lol if that came to fruition the trough would definitely pull it due Northward !!!

Perhaps. I dont think it would to the extent that the E. Gulf would have to worry about it; but I could see that set up aid in its gaining enough latitude to pose a potential threat to your guys in Texas.

Of course that's what I meant ! Yeah the Weather Channel says it could impact the Texas coast next week so it's definitely something to watch half of the models are split .... HWRF takes Harvey due North into the Gulf now ! It's a dangerous trend

How about just chill down...it is just too early to talk about the long-term forecast. Well the Channel says that could happen NEXT WEEK since it's still Friday today, and HWRF's forecast does not show an impact to Texas. By the way media always exaggerate things sometimes. So just sit down n' watch. Don't be some kind of aggressive.

[Thetxhurricanemaster]

Perhaps. I dont think it would to the extent that the E. Gulf would have to worry about it; but I could see that set up aid in its gaining enough latitude to pose a potential threat to your guys in Texas.

Of course that's what I meant ! Yeah the Weather Channel says it could impact the Texas coast next week so it's definitely something to watch half of the models are split .... HWRF takes Harvey due North into the Gulf now ! It's a dangerous trend

How about just chill down...it is just too early to talk about the long-term forecast. Well the Channel says that could happen NEXT WEEK since it's still Friday today, and HWRF's forecast does not show an impact to Texas. By the way media always exaggerate things sometimes. So just chill down and don't be some kind of aggressive.

I'm not saying it'll happen I'm just saying to stay on watch

[Alyono]

model ping pong continues. GFS now keeps the system alive

[chaser1]

model ping pong continues. GFS now keeps the system alive

Hmmm, I just took a look. Keeps it fairly weak and to the south. Still, will be interesting to see if it even maintains it during future runs

[Nimbus]

Moving pretty fast ATM and the latest convective burst indicates its not going to die off any time soon. Guess we watch the ULL currently over the keys to see if there is any indication it slows down and will take a position to pick this up.

[srainhoutx]

model ping pong continues. GFS now keeps the system alive

Look at that upper trough dropping S interacting with the TUTT. The models are clearly struggling. Need the NOAA Global Hawk missions and additional NWS Forecast Office special balloon launches next week.

[bubba hotep]

Getting a little feisty here at sunset

[Thetxhurricanemaster]

model ping pong continues. GFS now keeps the system alive

Look at that upper trough dropping S interacting with the TUTT. The models are clearly struggling. Need the NOAA Global Hawk missions and additional NWS Forecast Office special balloon launches next week.

GFS stalls this in the BOC for awhile !!!!

[stormreader]

With the latest discussion laying everything out, i'm gonna go out on a limb here. Assuming that Harvey will have at least maintained its identity as a closed system, I believe that the storm will undergo some significant strengthening at its crossing 70W and within the 24-36 hr. period. I'll further guess that Belize or Yucatan will have to brace for a Cat. 2 or 3 hurricane. As I see it, the cut-off centered over the Florida Straits will continue to not only move westward but more importantly will gain latitude as well. I think that the shear impacting Harvey now will lesson in about 24 hours as the storm moves a little further west and that we'll see a broader upper anticyclonic flow begin to bridge south and over the Central Caribbean. Obviously no models seems to think that and NHC seems to be hinting towards possibly better upper conditions but further out than that. Hmmm, maybe I wont quite bet the farm on it LOL; better I keep it to a 6-pack of beer!

Very bold. For the sake of your prediction--good luck!

[lrak]

Shoot, we haven't had a real threat since 1980 with Allen. I sure hope it doesn't form up like some are saying, I like my A/C and running water. I don't want to go to SA and get a hotel, my salt tank will die. Hopefully it'll just be a sheared storm with lots of beneficial rain. After reading all the posts on Storm2K of post hurricane strikes over the years has me a bit worried now, especially all the stories from Florida and Louisiana.

Hurricane Allen https://en.wikipedia.org/wiki/Hurricane_Allen#/media/File:Allen_1980_track.png

[stormreader]

Of course that's what I meant ! Yeah the Weather Channel says it could impact the Texas coast next week so it's definitely something to watch half of the models are split .... HWRF takes Harvey due North into the Gulf now ! It's a dangerous trend

How about just chill down...it is just too early to talk about the long-term forecast. Well the Channel says that could happen NEXT WEEK since it's still Friday today, and HWRF's forecast does not show an impact to Texas. By the way media always exaggerate things sometimes. So just chill down and don't be some kind of aggressive.

I'm not saying it'll happen I'm just saying to stay on watch

South Texas may be the "conservative" forecast. Going to say at least that. At least north of the border.

[Thetxhurricanemaster]

Shoot, we haven't had a real threat since 1980 with Allen. I sure hope it doesn't form up like some are saying, I like my A/C and running water. I don't want to go to SA and get a hotel, my salt tank will die. Hopefully it'll just be a sheared storm with lots of beneficial rain. After reading all the posts on Storm2K of post hurricane strikes over the years has me a bit worried now, especially all the stories from Florida and Louisiana.

Hurricane Allen https://en.wikipedia.org/wiki/Hurricane_Allen#/media/File:Allen_1980_track.png

If your in Texas this definitely needs to be watched ...

[stormreader]

Shoot, we haven't had a real threat since 1980 with Allen. I sure hope it doesn't form up like some are saying, I like my A/C and running water. I don't want to go to SA and get a hotel, my salt tank will die. Hopefully it'll just be a sheared storm with lots of beneficial rain. After reading all the posts on Storm2K of post hurricane strikes over the years has me a bit worried now, especially all the stories from Florida and Louisiana.

Hurricane Allen https://en.wikipedia.org/wiki/Hurricane_Allen#/media/File:Allen_1980_track.png

You're right. You guys are overdue (expecially for a major). And Allen was in some kind of a weakening phase as he approached the Brownsville area.
I think Celia '71 (from memory) may have been worse for Corpus. Cat 3??? I believe. Seems like it rounded the top of the Yucatan coast before heading to Corpus. From what I've read, the big one for Corpus was the great 1919 storm. Know for being extremely large and slow moving. But it came east to west across the GOM from the general direction of the keys. And in mid Sept too. Unusual that it had so little northerly component in Sept. Pressure 27.37 (all from memory--think I'm basically right).